Carburetor



' INVENTOR. G0fi6 N/hOLL E).

ATTORNEY.

,3 17m \Q1. 0 M

May 18, 1937. G. M. HOLLEY CARBURETOR Filed Jan. 28, 1956 V increased 50 or 90% Patented May 18, 1937 A UNITED STATES PATENT OFFICE CARBURETOR George M. Holley, Grosse Pointe Farms Mich. Application January 28, 1936, Serial No. 61,247,

4 Claims.

The object of this invention is to provide means whereby a. self-lift carburetor will automatically increase the lift on its fuel supply chamber when a car is climbing a hill and during the early stages of accelerating from a low engine speed. When a tank is located in the rear and the engine in front, the lift required increases from 22 inches to almost 50 inches on a 25% grade. Obviously, if the carburetor is designed to perform on the level, the air flow should be the greatest possible and therefore the resistance of the air valve will be as little as possible. Hence the resistance created by the air valve should be just suflicient to lift the fuel 22 inches when idling.

- When climbing a hill such an air valve will not create suflicient lift to raise the fuel to the float chamber of the car. I have discovered that if I hang a weight on the air valve less than 40, for example 20 from the vertical and arrange that this weight Swings out into the direction of motion of the vehicle so that when-the air valve is wide open, this weight is over 70 and less .than

90 to the vertical, then on ascending a hill the weight when idle will be effective torque of the depending on the steepness of the hill, whereas the effective torque when the air valve is wide open would only vary 1 Eflective pounds inch torque of one pound at a radius of 1" when the valve is inclined .from the vertical on a. hill is as follows:',

Idle Wide open Hill X1133: Torque X35: Torque Degrees Egg? Inch Inch pound pound 20 0.34 so 0.985 0 Level 0.50 90 1.00 10 17% 40 0.64 100 0. 985 20 34 The carburetor when running at high speed creates sufficient vacuum on the .fuel nozzle due to the high air velocity so that the fuel nozzle has no difliculty in taking the fuel away from the float chamber even though the float chamber has in it a vacuum of 50" .of gasoline. Hence, it is possible to maintain at all times sufiicient vacuum in the float chamber to climb any hill at high engine speed. The difficulty comes when it is required to idle the engine on a hill or to climb the hill with the engine running at low engine speed, wide open. -In either event, there is a shortage oflift and-this is especially noticeable when idling on a hill. Hence, a 50 to 90% increase in lift when idling on a hill is desirable.

By arranging that the weight swings from about 20 to 30 when idling and from 80 to 90 wide open, I can obtain the desired result, name- 5 1y, an air valve which automatically increases the lift when idling on a hill and does not change the resistance to air flow appreciably when an engine is running at high engine speed on a hill.- The power of the interfered with but the performance at part throttle and low engine speed is greatly improved. During acceleration from 7 M. P. H. at say 3 or 4 feet per second, obviously there is a greater demand for'fuel and to this demand the 'weighted air valve responds- As the car gains speed the weight assumes its horizontal position and the effect of acceleration disappears automatically.

Figure 1 shows retor in the position it assumes when climbing an extremely steep hill.

Figure 2 shows the corresponding parts with the air valve substantially wide open.

In the figures, an air valve II is counterbal- 25 anced by a weight l2, the center of gravity of' which is at A. The center of the air valve H is at B. A vertical ordinate B-C dropped from the center B and a corresponding ordinate A-D dropped from the that the weight l2 has a leverage C-D around the center B. When the carburetor is horizontal, that is, when the plane E-F is horizontal, the vertical ordinate B-G dropped from the center B and the vertical ordinate A-H dropped from 35 the center of gravity A perpendicular to the plane EF demonstrates that the leverage of the weight l2 around the center B is equal to G-H.

If JK indicates the horizontal plane when climbing a hill indicated by the plane EF, then 40 the effect of going from the horizontal plane JK to the inclined plane EF Will be to in: crease the leverage of the weight l2 around the center B'from the leverage GH to the leverage CD. It will be noted that this is due to the fact that the angle B-A makes with the line BG is small. When this angle increases, that is, when the air valve ll opens, the effect ofgoing from the horizontal plane JK to the hill engine at top speed is thus not diagrammatically the carbu- 20- centerof gravity A indicate 30 indicated by the plane E,-F will be negligible.

I3 is the air entrance. is the cylindrical It is noted that this ade is weight l2 moves.

air valye l l. I6

under the depression below the I is the stop in the air entrance l3 agf'ainst which the air valve II comes to rest When the engine is not running. l1 isthe entrance to the air bypass'around the air valve l I. The air drawn through this bypass passes through the small venturi l8- and discharges through the tube 19; This tube l9 terminates in the throat 20 of the main 'air passagu Located in this throat 20 is the throttle M. The tube l9 terminates adjacent to this throttle as shown in my co-pending patent Serial No. 744,160. The throat 20 discharges into the mixture outlet 45 with which it forms a Venturi passage.

Fuel is supplied from a tank, not shown, to a pipe 22 through the float valve 23 controlled by the float 24. Float valve 24 is contained in a float chamber 25, the upper part of which 26 communicates through a pipe 21 with the throat of the venturi 28. A second air bypass 29 supplies air from the air entrance l3 to this venturi 28 and to the passage 30 which communicates through the restriction 3| to the underside of the air valve H, the :area of which restriction 3| is controlled by a needle valve 32 which is connected by means of a link 33 with the air valve ll.

It will be noted that the air flowing through the passages 29, 28, 30, and 3| discharge into the space l5 in which the weight l2 swings, that is, on the vacuum side of the air valve II. The

air 'valve thus controls the depression in the upper part 25 of the float chamber 25. The flow of fuel from the float'chamber 25 to the small venturi I8 .is controlled by the throttle in the following manner; A -th'rottle lever 34 controls the movement of the'throttle 2|: -A lever 35 is connected through a .link .36 with a rocking lever 31 which is connected through-a link 38 with a hook-39, which carries the needle valve or economizer pin'jp. This economizer pin is guided'initube ll and controls the fuel flow a passage ing in which the air valve ll rotates. I5 ;4ti1 {-ou is the space back of this housing in which th restriction 42 which is connected by l3 with the orifices 44 located in the down stream side of the throat of the small venturi l8.

Figure 2 shows the position the weight l2 assumes when the airvalve II is wide open.

What I claim is:

1. A fuel lift carburetor for motor vehicles having an air entrance, an automatic valve therein, a mixing chamber, a mixture outlet therefrom, a throttle valve therein, a fuel supply chamber, a fuel passage leading therefrom discharging into the throat of a Venturi passage through which air is bypassed into said mixing chamber around said air valve, a second venturi passage through which air is also bypassed around said air valve into said mixing chamber, a passage connecting the throat of said second venturi with the upper part of said fuel supply chamber so as to create a vacuum therein, means for increasing this vacuum when a vehicle is ascending a hill, comprising a weight attached to said air valve and adapted to swing as the air valve opens into the direction of motion of the vehicle. I

2. In a fuel lift carburetor as described in claim 1 in which the plane passing through the axis of the swinging weight and its center of gravity is substantially horizontal when the air valve is wide open and the vehicle is moving in the horizontal plane.

3. A fuel lift carburetor as described, in claim 1 in which the plane passing through the axis of the swinging weight and its center of gravity is less than to the vertical when the air valve is in its closed position and the vehicleis on a horizontal plane.

4. A fuel lift carburetor as described in claim 1, in which the center of gravity of the swinging weight oscillates in a substantially vertical plane 

